When, upon the day after our arrival at Mamanui, we followed up the creeks where we had been camped, and ascended these mountains to a height of 4000 feet, I found all these rocks _in situ_, but, owing to the densely wooded nature of the country, it was only in the ravines that the geological formation could be examined. The clay slates were placed more or less vertically, by reason of the intrusion of the diorite bars through their plane, while the quartz I found on the slopes of the hills and in abundant quantities in the creeks, and from the auriferous indications which I noticed on all sides, I much regretted that, owing to the necessity to press on our journey, I was prevented from examining this country more closely. I am, however, firmly of opinion that this extensive range, which presents many features in common with the Sierras of California, offers to the geologist a rich field for research, and to the miner a probable El Dorado where, I believe, great treasure will be brought to light in years to come. It is more than likely that the whole of this extensive mountain range will be found upon examination to be rich in all the mineral products common to geological formations of a like kind, and that not only gold but other minerals will be found. It is likewise worthy of note that the natives of this district with whom we afterwards came in contact assured us of the existence of gold in these mountains, as likewise of a mineral which, by the description they gave of it, I judged to be silver. Although it is impossible to define by any theoretical course of reasoning what hidden treasures may exist in the fastnesses of the Kaimanawas, there can be no doubt that the whole region is well worthy an extended examination. The discovery of a payable gold-field in this locality could not fail to confer a material benefit upon the whole country. Situated as these mountains are in the centre of the island, they are easily accessible from all points; and if once the existence of remunerative auriferous deposits were established, the spread of population would follow, and in this way the vast and varied resources of an extensive portion of the colony would be developed. CHAPTER XX. SECOND ASCENT OF RUAPEHU. SOURCES OF THE WHANGAEHU AND WAIKATO RIVERS. Curious parterres--Supposed source of Whangaehu--A gigantic lava bed--A steep bluff--The Horseshoe Fall--The Bridal Veil Fall--The Twin Falls--A dreary region--Ice caves--Source of the Waikato--The descent--Our camp on the desert.